Adjustable electric-lamp support



D. J. M CARTHY ADJUSTABLE ELEV/T810 LAMP SUPPORT Original Filed April 28. L921 ltl Unitarian sitar DAR-[13L J. M'CUARTHY, (4F ELGIN, ILLINOIS, ASSIGNOR TO CHICAGO -RAlIIrWAY SIG- NAL .P

I FIJI QOMYANY, A. CORPORATION OF ILLINOIS.

ADJUSTABLE ELECTRIC-LAMP SUPPORT.

original application filed April 28, 1921, Serial No. l65,143. Divided and this application filed January {i methocl of adjusting original and re r .r mont lamps and wherein this support may be used is claimed in my copending ap plication Serial No. 4651143: filed April 28.

192i. of which this application-is a division.

in many fields, such for exan'lple as railway signalling, it is often desirable and necessary to position electric lamps in a particular position relative to the loci of lens and reflector systems. Many of the signals must he placed in. relatively inacccssihle or (lifticultl accessible positions. such as the tops of poles. switches. signal towers. etc. The accurate replacement of burned out and do fective lamps in such situations is some times impossible and always dillicult and expensive. Laboratory mothorlsin the. field are out of the question. v

*(lne of the objects of this invention is to provide an improved adjust able support for electric lamps for signal and similar purposes. 4

Another. object is to provide a support whereby the position of a lamp relative to the focus may he quickly and reliably adjusted.

Another object is to provide a support which may be readily operated to give accurate adjustment oven in relatively inac (-essible and dillieult positions.

-Another ohjeet is to provide a support reliable. inexpensive and olliciont.

objects and advantages will herenpeas'.

n einhodin'icnt oi -the invention is illustrated in the accompanying drawing, Whereim the support shown in position in a double lens l: o and coop ."ating with a Serial No. 529,434.

focus finder by means of which the source of light may be readily positioned in proper relation to the lenses.

The views in the drawing are as follows:

1 is an elevation of a rear-view of a light unit showing the focus finder in place thereon.

Fig. 2 is a vertical section taken on line 2-2 of Fig. 1. I

, Fig. 3 is a view similar to Fig. 2, showing a fragment thereof.

Fig. 4 is an enlarged sectional view of a part of the lamp adjusting support taken on line 4-4' of Fig. 2.

Fig. 5 is a similar View to Fig. t taken on line 5 5 of Fig. 2.

Fig. 6 is asection of part of the focus finder taken on line 66 of Fig. 2.

Fig. 7 shows a view in side elevation of the conventional filament of an electric lamp.

Fig. 8 is a diagram of the focus finder with the lamp displaced, 0n the focal axis and forward of the focal point.

In all the views the same reference characters are employed to indicate similar parts.

To obtain the highest efficiency in the projection of light by lenses, reflectors, or'the like, it is quite essential that the source of light, such as the filament of an electric lamp, be placed at the exact focal point of the projector; when this has been achieved the light may be made, by-use of a proper ar angement of lenses, to produce a beam light in which the rays are in parallel lines, thus projecting a more intense and far reaching beam of light. By moving the lamp along the focal axis of the light projector towards the projector the rays may be made to outwardly diverge or flare while if the lamp be moved out of the focal point in the opposite direction the rays of light may thus be made to converge.

In railway signal systems, in difierent situations, the signal lamp units are required to project beams of light in which the rays are parallel; in other locations the rays of light must be diverging so as to extend over a relatively large light field at the objective point, and in others the light beam must he more concentrated at the point of application. For. uniformity of apparatus and economy of equipment, it is highly desirable tnat a single structurebe made capable, by

proper ad ustment, to meet the varionsire cisely the same location of the filament of the lamp initially installed in the unit,

whereby it will produce the same results as the latter, although it may vary in some of its structural features or other characteristics from the ori inal lamp. a

The drawings 510W portions of a more or less conventional signal lamp unit in which 10 is a part of the unit casing providing aring 11 for a lens 12, and a ring 13 for a lens 14:. In this doublet arrang ment of lenses, when the filament 15 of the electricvlamp is lbcated atthe precise focalpoint, as shown in. Fig. 2, the raysof light projected therefrom will form a beam in which the rays will extend in parallel lines. If the light point 15 be brought nearer to the smaller lens, the light beam will be more or less fan shape and if it be moved in the opposite direction, the beam of light will be concentrated.

A means for moving the lamp and secur ing it in its desired position is accomplished by the following instrumentality.

A, bracket 17 carries lamp sockets 18 and 19, the lamp 16 is shown inserted in the latter, and is the active lamp of the unit. Socket 18 may be used to hold an extra to replace the active lamp in socket 19, should the same be broken or burned out. Thebracket is carried by or is part of a tube or sleeve 20, which is threaded at one end, as at 21.

A rotatable shaft 22 carries one end an eccentric 23 to which it is fixed thru the annular sleeve 23; at its other end it is fixedto an eccentric 25 by a pin 26. These eccentrics form journals upon which the shaft is rotatably supported and while they are shown to be somewhat difierent in dia .Inetric dimensions, the throw or eccentric ty of the two eccentrics is the'sarne so that, they act one eccentric and upon. rotation, the shaft 22will he moved in parallel lines around the axis of its movement. The shait and sleeve 23" are provided with a screw driver slot 27 for convenience of rotation ori'they may be rotated by a wrench engaging the annular-sleeve 23, The eccentric 25 is rotatable freely in a socket 28. which is a fixed part of theframe 10. To retain at its inner end neonate eccentric 25 in the socket it is provided with a groove 29 into a screw 30 projects from the socket28. I

The eccentric 23 is rotatable in a ring 31 which is part'of a rearwardly extending arm 32, which also carries the eccentric caring or socket 28. Ai'm'32 is bifurcated rovldi arms 33 and 34. red to screws 35. I i

A tube or sleeve 36 overliesa lar e portion of shaft 22 and is freely rotatable with respect thereto. It is provided with an axially parallel slot 37 into which a screw 38, from the bracket sleeve 20, projects to permit the latter slesvoito be axially moved thereon and to canse said sleeves 20 and 36 to be rotated as one.

A nut 39, rotatable on the sleeve 36, is prevented from being axially moved thereon by a screw 40, which extends therefrom into an annular groove 41 in the sleeve. The sleeve 36 is normally held in fixed position with respect to the frame 10 by a set screw 41 which passes thrua hub d2 of sleeve 23'. The screw 41"is held in clamping position by a nut 43. "he -eccentric 23 is lined by a set screw 44: which passes thru the hub 45 of ring 31, which is a part of the frame 10. A check nut 46 securely holds the clamping set screw 44 in clamping position.

From the above description it will be manifest that the lamp 16 may be movcdto any desired point in a plane transverse to the focal axis of the lens combination by rotation of the shaft 22 and its connected eccentrics and that it may also be moved along the focal axis rotation of the nut 39 and fixed in its adjusted positions by the set screws 43. and 44.

At the time when the light signal unit is assembled, lamp 1% is placed in the socket i9 and its filament energised. filament is then placed approximately at focal point of the lens co binaticn.

.TiiG been: of light the outer lens now measured photon tricelly. The lamp and filament are then movably adjnstcd and readings taken from the photometer until the exact focal point has been thus ascertained, whereupon the shlftableparts of'tne lamp ad nsting dev ce are locked in fixed positions y the set screws. (if

course, if it is desired to have the signal supplementary The original shop method of finding the desired location or focal point, can not be pursued for placing a new lamp because the.

unit is supported on a pole or other inaccessible location and for this reason it is impractical or impossible to follow the original procedure outlined above.

I have therefore provided a focus finder and a method for reestablishing the initial relation witha substitute electric lamp and its associated lenses.

The instrument consists of a small closed casing 50 having an observation aperture 51. A portion of its edge wall is incurved. as at 52, the curved portion extending something more than 90 degrees and having portions of its wall inclined at degrees from the perpendicular, as at 53 and 54. A small len. is secured .n an opening in the curved portion 52 of the housing wall vertically above the filament in said curved wall just 90 degrees removed. A light reflector 57 is secured to the wall 54, inclined just 45 degrees -from the focal axis of the lens 553. A similar mirror or reflector 58 is fixed in the same manner to the inclined wall 53 and inclined 45 degrees from the focal axis of the lens so that the beams of light refiected from the mirrors or reflectors 57 and 58 will be in planes precisely 90. degrees in angular relation to each other.

A. plate of ground glass 5.9 is placed in the path of the beam 60 of reflected light and located at right angles thereto, upon which to receive the image 15 of the lamp filamerit 15.

A plate of ground glass 61 is placed in the path of the beam 62 of reflected light from the lens 56 and located at right angles there to, upon which to receive the image 15 ot' the lamp filament 15.

A reflector 62 is placed over the plate 61 and inclined substantially 45 degrees so that an observer looking thru the aperture 51 will see the two reflected images 15 and 15 as they appear in Fig. 1, when the lamp filament 15 is in the position occupied bv the original lamp which is the focal point of the lens comhinationf The plates 59 and 61 each have a longitudinally extending central line 63 which blend into the line 63 as they appear to the observer in Fig. 1. They each have a trans versely extending line 64 and 65. respectivi ly. Vhen the images 15 and 15" are symmetrical with respect to the associated transverse lines and with respect to the single vertical line 63, as shown, the former relations of the light point of the lamp and lenses havebeen reestablished and the signal uni will operatewith the new lamp in the manner as before its original lamp became defective.

Should adjustment he required to produce divergence of light rays of degrees,

angle of the light beam 60 is raised above the line 65, in a manner clearly apparent. in which event the image wlll be raised to the short lines 5, 10 or 15, according to .the degree of beam expansion, on the plate 59, shown more clearly in Fig. 1indicative of the respective degrees to which the light beam has been spread by the forward move ment of the lamp 16.

Since, in the above example, the lamp is moved along the focal axis of the lens, there will be no disturbance of the light projected thru lens 56; therefore the image 15 will remain on cross line 6%.

To adjust the instrument to a lamp signal unit in which the electric lamp has been located, in the manner heretofore described, so that it may he removed and subsequently replaced with accuracy, the easing 50 has projecting forwardly therefrom a tapered stem 66, having a transverse notch 67 in its smaller free end. At approximately the proper position in the frame 1.0 a socket- 68 is made, which is considerably larger than stem 66. A sleeve 69, the bore of which is tapered to neatly fit the stem 66, has one or more grooves 70 and a transverse pin 71 which the transverse notch 67 of the stem engages to prevent rotation of the stem and attached instrument.

When the filament 15 has been properly located by adjustment of the instrument the latter is lined and temporarily held. with the stem 66 and sleeve 69 in the socket 68., and with the image 15 and 15 as shown in Fig. 1. Then metal such as Babbitt metal, zinc or lead. 72. is poured into the socketand around the sleeve 69 to hold the latter in place in the socket. The instrument will now visually show the truefocal point or the lens, and may be removed and reinserted for subsequent use.

The instrument may advantageously on used. in connection with a parabolic reflector, or other reflector.

Having described my invention what I claim as new and desire to secure by Letters Patent, is

1. In a device for adjusting the position of a lamp. a rotatable shaft; two like eccentrics one on each end thereof; atube rotatable on said shaft; a lamp bracket carried by the tube; means/to move the tube and lamp bracket axially of the axis of the tubeymeans to lock the tube and shat to get'her to prevent relative rotation; and

means to lock the shaft and tube to a fixed part or the structure.

1 mmww 2. I31 a devie for adjusting $319 psaitinn 30 receive thei amp carried by said flaw; 0f Qfiamp, $1 rotatabla shaft; an eccentric a" nut eggagifig, sald sleeve t0 mdieit, said 10 secured to each end of the shaft to provide socket and. lamp axially of the tube; and' journals for the shaft; fixed bearings in means tnleck said shaft tube and-sleeve to 5' which the eccentrics aweretatable, respecprevnt their rotation. v

lively; a tuba rotatable 0n the shafi; a In testimony whereaf I hereunto set my threaded sieeve axially movable on said mks hand. f and rotatable therewfih; a lamp; :2 socket J.'MCGARTHY. 

